High voltage deflection circuit

ABSTRACT

A resonant pulse voltage having a positive polarity is applied by a first resonant circuit and a third resonant circuit to a horizontal deflection coil included in the first resonant circuit, and a resonant pulse voltage having a negative polarity which is opposite to that of resonant pulse voltages applied by the first resonant circuit and the third resonant circuit is applied to only a horizontal deflection coil in the first resonant circuit without being applied to a transistor by a second resonant circuit.

TECHNICAL FIELD

[0001] The present invention relates to a high voltage deflectioncircuit for supplying a deflection current to a deflection coil, andmore particularly, to a high voltage deflection circuit that supplies adeflection current to a horizontal deflection coil in a televisionreceiver.

BACKGROUND ART

[0002] In cathode-ray tubes (CRTs) for image display used for televisionreceivers, a horizontal deflection circuit and a vertical deflectioncircuit that respectively supply a horizontal deflection current and avertical deflection current to a horizontal deflection coil and avertical deflection coil are used, and electronic beams sent out of anelectronic gun are deflected in the horizontal direction and thevertical direction by the operations of the circuits.

[0003]FIG. 21 is a circuit diagram showing an example of theconfiguration of a conventional horizontal deflection circuit. Theconventional horizontal deflection circuit shown in FIG. 21 comprises ahorizontal switching transistor (hereinafter referred to as atransistor) Q11, a resonant capacitor C11, a damper diode D11, ahorizontal deflection coil L12, an S-correction capacitor C12, and aprimary coil L11 of a deflection transformer.

[0004] One end of the primary coil L11 of the deflection transformer isconnected to a power supply V11, and the other end thereof is connectedto a node N11. The transistor Q11 has its collector connected to thenode N11, its emitter connected to a ground, and its base to which adrive pulse DP which is synchronized with the horizontal frequency isapplied.

[0005] The resonant capacitor C11 and the damper diode D11 are connectedin parallel between the node N11 and a ground terminal. The horizontaldeflection coil L12 and the S-correction capacitor C12 are connected inseries between the node N11 and the ground terminal. The resonantcapacitor C11, the damper diode D11, the horizontal deflection coil L12,and the S-correction capacitor C12 constitute a resonant circuit.

[0006] By the above-mentioned configuration, when the transistor Q11 isrendered conductive upon application of the drive pulse DP which issynchronized with the horizontal frequency to the transistor Q11, energyis supplied to the resonant circuit from the power supply V11 throughthe primary coil L11 of the deflection transformer. Accordingly, adeflection current having a predetermined slope flows through thehorizontal deflection coil L12.

[0007] When the transistor Q11 is then rendered nonconductive, theresonant circuit resonates, whereby a resonant pulse voltage isgenerated by the energy previously stored. Consequently, a resonantpulse voltage is applied to the horizontal deflection coil L12 by theresonant circuit, so that a deflection current having a slope in theopposite direction to the predetermined slope flows through thehorizontal deflection coil L12.

[0008] By repeating the above-mentioned operations, a sawtoothdeflection current flows through the horizontal deflection coil L12.Consequently, a magnetic field is generated in the deflection coil L12,thereby making it possible to successively deflect electronic beams inthe horizontal direction.

[0009]FIG. 22 is a block diagram showing another example of theconfiguration of the conventional horizontal deflection circuit. Theconventional horizontal deflection circuit shown in FIG. 22 comprises ahorizontal switching transistor (hereinafter abbreviated as atransistor) Q11, a power supply unit 101, a first resonant circuit 102,and a second resonant circuit 103.

[0010] The transistor Q11 has its collector connected to the powersupply unit 101 and the first resonant circuit 102, its emitterconnected to a ground, and its base to which a drive pulse DP which issynchronized with the horizontal frequency is applied. The firstresonant circuit 102 comprises a horizontal deflection coil. The firstresonant circuit 102 and the second resonant circuit 103 are connectedin series. The first resonant circuit 102 is connected to the powersupply unit 101, and the second resonant circuit 103 is grounded.

[0011] In the above-mentioned manner, resonance operations performed bythe first and second resonant circuits 102 and 103 which are connectedin series are controlled by the transistor Q11, so that a resonant pulsevoltage is generated by the first and second resonant circuits 102 and103 using energy supplied from the power supply unit 101.

[0012]FIG. 23 is a circuit diagram showing the configuration of theconventional horizontal deflection circuit shown in FIG. 22. Theconventional horizontal deflection circuit shown in FIG. 23 comprises atransistor Q11, resonant capacitors C11 and C13, damper diodes D11 andD12, a horizontal deflection coil L12, a resonant coil L13, S-correctioncapacitors C12 and C14, and a primary coil L11 of a deflectiontransformer.

[0013] One end of the primary coil L11 of the deflection transformer isconnected to a power supply V11, and the other end thereof is connectedto a node N11. The power supply V11 and the primary coil L11 of thedeflection transformer constitute the power supply unit 101 shown inFIG. 22. The transistor Q11 is the transistor Q11 shown in FIG. 22, andhas its collector connected to the node N11.

[0014] The resonant capacitor C11 and the damper diode D11 are connectedin parallel between the node N11 and a node N12. The horizontaldeflection coil L12 and the S-correction capacitor C12 are connected inseries between the node N11 and the node N12. The resonant capacitorC11, the damper diode D12, the horizontal deflection coil L12, and theS-correction capacitor C12 constitute the first resonant circuit 102shown in FIG. 22.

[0015] The resonant capacitor C13 and the damper diode D12 are connectedin parallel between the node N12 and a ground terminal. The resonantcoil L13 and the S-correction capacitor C14 are connected in seriesbetween the node N12 and the ground terminal. The resonant capacitorC13, the damper diode D12, the resonant coil L13, and the S-correctioncapacitor C14 constitute the second resonant circuit 103 shown in FIG.22.

[0016] By the above-mentioned configuration, a horizontal deflectioncircuit of a diode modulator type capable of correcting pincushiondistortion and horizontal amplitude without varying a high voltageoutput generated by the deflection transformer is constructed.

[0017]FIG. 24 is a timing chart for explaining the operations of thehorizontal deflection circuit shown in FIG. 23. As shown in FIG. 24,when the transistor Q11 is rendered conductive (an ON period T2 shown inFIG. 24) upon application of a drive pulse DP which is synchronized withthe horizontal frequency to the transistor Q11, energy is supplied tothe first and second resonant circuits 102 and 103 from the power supplyV11 through the primary coil L11 of the deflection transformer, so thata deflection current IC having a predetermined slope flows through thedeflection coil 13.

[0018] When the transistor Q11 is then rendered non-conductive (an OFFperiod T1 shown in FIG. 24), the first resonant circuit 102 and thesecond resonant circuit 103 respectively resonate, whereby resonantpulse voltages are respectively generated by the energy previouslystored. Consequently, a resonant pulse voltage P is applied to thehorizontal deflection coil L12 by the first resonant circuit 102 and thesecond resonant circuit 103, so that a deflection current IC having aslope in the opposite direction to the predetermined slope flows throughthe horizontal deflection coil L12.

[0019] By repeating the above-mentioned operations, a sawtoothdeflection current IC as shown in FIG. 24 flows through the horizontaldeflection coil L12. Consequently, a magnetic field is generated in thedeflection coil L12, thereby making it possible to successively deflectelectron beams in the horizontal direction.

[0020] In recent years, in the television receiver, the frequency isincreased in a high-definition television, a monitor for a computer, andso forth, so that the horizontal frequency is liable to be increased.When the horizontal frequency is increased, the pulse width of theresonant pulse voltage P is narrowed. However, the amount of energy inthe resonant pulse voltage P is determined by a power supply voltage.When the pulse width is narrowed, therefore, the pulse height isincreased.

[0021] However, the pulse height of the resonant pulse voltage P islimited by the voltage resistance of the transistor Q11. Accordingly,the pulse height of the resonant pulse voltage P cannot be increased asit is. In order to obtain a predetermined deflection current, therefore,the inductance value of the horizontal deflection coil L12 must bedecreased. When the inductance value is decreased, it is difficult toadjust a magnetic field generated by the horizontal deflection coil L12.Accordingly, the optical characteristics and the deflection distortionof the electron beams released form the cathode-ray tube are degraded.

[0022] Furthermore, the deflection current is inverse proportional tothe inductance value of the horizontal deflection coil L12. When theinductance value of the horizontal deflection coil L12 is decreased,therefore, the deflection current is increased. Accordingly, the loss ofpower in each of electric devices through which the deflection currentflows is increased, thereby increasing power consumption.

DISCLOSURE OF INVENTION

[0023] An object of the present invention is to provide a high voltagedeflection circuit capable of increasing the inductance value of adeflection coil to improve the optical characteristics and thedistortion characteristics of a cathode-ray tube as well as reducing adeflection current to reduce power consumption.

[0024] Another object of the present invention is to provide a highvoltage deflection circuit capable of increasing the inductance value ofa deflection coil to improve the optical characteristics and thedistortion characteristics of a cathode-ray tube as well as reducing adeflection current to reduce power consumption, and further capable ofstably performing a circuit operation.

[0025] A high voltage deflection circuit according to an aspect of thepresent invention is a high voltage deflection circuit for supplying adeflection current to a deflection coil, comprising first resonant meansincluding the deflection coil for applying a first resonant pulsevoltage to the deflection coil; switching means connected to the firstresonant means for performing a switching operation in response to apredetermined drive signal; and second resonant means connected inseries with the deflection coil and supplied with a drive voltage by aresonance operation of the first resonant means for applying to thedeflection coil a second resonant pulse voltage having an oppositepolarity to that of the first resonant pulse voltage.

[0026] In the high voltage deflection circuit according to the presentinvention, the second resonant means is connected in series with thedeflection coil included in the first resonant means, and the switchingmeans for performing the switching operation in response to thepredetermined drive signal is connected to the first resonant means.Accordingly, the first resonant pulse voltage is applied to thedeflection coil by the first resonant means, and the second resonantpulse voltage having an opposite polarity to that of the first resonantpulse voltage is applied to the deflection coil by the second resonantmeans.

[0027] At this time, the pulse voltage applied to the deflection coil isthe sum of the first and second resonant pulse voltages, so that a pulsevoltage greater than the first resonant pulse voltage can be applied tothe deflection coil. Further, the second resonant pulse voltage is notapplied to the switching means, and only the first resonant pulsevoltage is applied thereto, so that a pulse voltage lower than the pulsevoltage applied to the deflection coil can be applied to the switchingmeans.

[0028] Consequently, the pulse voltage applied to the deflection coilcan be increased without being limited by the voltage resistance of theswitching means. Accordingly, it is possible to increase the inductancevalue of the deflection coil to improve the optical characteristics andthe distortion characteristics of a cathode-ray tube as well as toreduce a deflection current to reduce power consumption.

[0029] The first resonant means may be supplied with electric powerthrough a first coil of a deflection transformer connected to a powersupply, and the second resonant means may comprise a resonant capacitor,and a switching device connected in parallel with the resonant capacitorand supplied with a voltage obtained by smoothing a pulse voltage as apower supply voltage, the pulse voltage having an opposite polarity tothat of the first resonant pulse voltage and being induced in a secondcoil of the deflection transformer by the first resonant pulse voltage.

[0030] In this case, the electric power is supplied to the firstresonant means through the first coil of the deflection transformerconnected to the power supply, and the voltage obtained by smoothing thepulse voltage having an opposite polarity to that of the first resonantpulse voltage and induced in the second coil of the deflectiontransformer by the first resonant pulse voltage is supplied as the powersupply voltage to the switching device connected in parallel with theresonant capacitor in the second resonant means. Consequently, only thefirst resonant pulse voltage by the first resonant means can be appliedto the switching means connected to the first resonant means withoutapplying the second resonant pulse voltage by the second resonant meansto the switching means.

[0031] The second resonant means may further comprise drive means forproducing a switching device drive signal using a pulse voltage havingan opposite polarity to that of the first resonant pulse voltage andinduced in a third coil of the deflection transformer by the firstresonant pulse voltage, and the switching device may perform a switchingoperation in response to the switching device drive signal for producedby the drive means.

[0032] In this case, the switching device performs the switchingoperation in response to the switching device drive signal for aproduced using the pulse voltage having an opposite polarity to that ofthe first resonant pulse voltage and induced in the third coil of thedeflection transformer by the first resonant pulse voltage. Accordingly,the second resonant means performs a resonance operation in response tothe resonance operation performed by the first resonant means, therebymaking it possible to apply the second resonant pulse voltage to thedeflection coil in synchronization with the first resonant pulsevoltage.

[0033] The second resonant means may further comprise drive means forproducing a switching device drive signal on the basis of the drivesignal, and the switching device may perform a switching operation inresponse to the switching device drive signal by the drive means.

[0034] In this case, the switching device performs the switchingoperation in response to the switching device drive signal produced onthe basis of the drive signal of the switching means. Accordingly, thesecond resonant means performs a resonance operation in response to theresonance operation performed by the first resonant means, therebymaking it possible to apply the second resonant pulse voltage to thedeflection coil in synchronization with the first resonant pulsevoltage.

[0035] The second resonant means may further comprise current-voltageconversion means for converting a current flowing through the resonantcapacitor into a voltage to produce a switching device drive signal, andthe switching device may perform a switching operation in response tothe switching device drive signal produced by the current-voltageconversion means.

[0036] In this case, the switching device performs the switchingoperation in response to the drive signal for switching produced byconverting the current flowing through the resonant capacitor into thevoltage. Accordingly, the second resonant means performs a resonanceoperation in response to the resonance operation performed by the firstresonant means, thereby making it possible to apply the second resonantpulse voltage to the deflection coil in synchronization with the firstresonant pulse voltage.

[0037] The drive signal may be a drive signal which is synchronized withthe horizontal frequency.

[0038] In this case, the switching means performs the switchingoperation in response to the drive signal which is synchronized with thehorizontal frequency. Accordingly, the high voltage deflection circuitaccording to the present invention can be used as a horizontaldeflection circuit, thereby making it possible to realize a horizontaldeflection circuit having a high operation frequency.

[0039] The first resonant means may comprise an S-correction capacitorconnected in series with the deflection coil, a resonant capacitorconnected in parallel with the deflection coil, the second resonantmeans and the S-correction capacitor, and a damper diode connected inparallel with the resonant capacitor.

[0040] In this case, pincushion distortion can be corrected bymodulating a power supply voltage for a power supply unit.

[0041] The high voltage deflection circuit may further comprise thirdresonant means connected in series with the first resonant means throughthe second resonant means for performing a resonance operation inresponse to the switching operation of the switching means.

[0042] In this case, a high voltage deflection circuit of a diodemodulator type can be realized by the first and third resonant means.

[0043] The first resonant means may comprise a first S-correctioncapacitor connected in series with the deflection coil, a first resonantcapacitor connected in parallel with the deflection coil and the firstS-correction capacitor, and a first damper diode connected in parallelwith the first resonant capacitor, and the third resonant means maycomprise a resonant coil, a second S-correction capacitor connected inseries with the resonant coil, a second resonant capacitor connected inparallel with the resonant coil and the second S-correction capacitor,and a second damper diode connected in parallel with the second resonantcapacitor.

[0044] In this case, a high voltage deflection circuit of a diodemodulator type can be constituted by the first and third resonant means.Accordingly, pincushion distortion can be corrected without varying ahigh voltage output generated by the deflection transformer bymodulating a current flowing through the second S-correction capacitor.

[0045] The high voltage deflection circuit may further comprise voltagesupply means for supplying a drive voltage to the second resonant meansuntil the second resonant means starts a resonance operation.

[0046] The drive voltage is supplied to the second resonant means by theresonance operation performed by the first resonant means, and thesecond resonant means attempts to generate the second resonant pulsevoltage. Unless a sufficient voltage to drive the second resonant meansis applied as the drive voltage supplied by the resonance operationperformed by the first resonant means, the resonance operation performedby the second resonant means may not, in some cases, be stabilized.Therefore, the drive voltage is supplied to the second resonant means bythe voltage supply means before the second resonant means starts theresonance operation, thereby making it possible to stably operate thesecond resonant means irrespective of the timing of the drive voltagesupplied by the resonance operation performed by the first resonantmeans.

[0047] Consequently, the pulse voltage applied to the deflection coilcan be increased without being limited by the voltage resistance of theswitching means. Accordingly, it is possible to increase the inductancevalue of the deflection coil to improve the optical characteristics andthe distortion characteristics of a cathode-ray tube as well as tofurther reduce a deflection current to reduce power consumption.Further, it is possible to stably perform a circuit operation.

[0048] The first resonant means may be supplied with electric powerthrough a first coil of a deflection transformer connected to a powersupply, the second resonant means may comprise a resonant capacitor, anda first switching device connected in parallel with the resonantcapacitor and supplied with a voltage obtained by smoothing a pulsevoltage as a power supply voltage, the pulse voltage having an oppositepolarity to that of the first resonant pulse voltage and being inducedin a second coil of the deflection transformer by the first resonantpulse voltage, and the voltage supply means may supply the drive voltageto the first switching device until the second resonant means starts theresonance operation.

[0049] In this case, the electric power is supplied to the firstresonant means through the first coil of the deflection transformerconnected to the power supply, and the voltage obtained by smoothing thepulse voltage having an opposite polarity to that of the first resonantpulse voltage and induced in the second coil of the deflectiontransformer by the first resonant pulse voltage is supplied as the powersupply voltage to the first switching device connected in parallel withthe resonant capacitor in the second resonant means. Further, the drivevoltage is supplied to the first switching device by the voltage supplymeans until the second resonant means starts the resonance operation.

[0050] Consequently, only the first resonant pulse voltage by the firstresonant means can be applied to the switching means connected to thefirst resonant means without applying the second resonant pulse voltageby the second resonant means to the switching means. Further, the drivevoltage is supplied to the first switching device by the voltage supplymeans until the second resonant means starts the resonance operation.Accordingly, a sufficient voltage to drive the first switching devicecan be supplied before the first resonant means performs the resonanceoperation, thereby making it possible to always stably operate thesecond resonant means.

[0051] The voltage supply means may comprise an external power supplyfor supplying the drive voltage to the first switching device until thesecond resonant means starts the resonance operation.

[0052] In this case, the drive voltage is supplied to the firstswitching device by the external power supply until the second resonantmeans starts the resonance operation. Accordingly, a sufficient voltageto drive the first switching device can be supplied before the firstresonant means performs the resonance operation, thereby making itpossible to always stably operate the second resonant means.

[0053] The voltage supply means may comprise a DC power supply, and asecond switching device that supplies the voltage to the first switchingdevice as a drive voltage from the DC power supply until the secondresonant means starts the resonance operation.

[0054] In this case, the voltage from the DC power supply is supplied asthe drive voltage to the first switching device by the second switchingdevice until the second resonant means starts the resonance operation.Accordingly, a sufficient voltage to drive the first switching devicecan be supplied before the first resonant means performs the resonanceoperation, thereby making it possible to always stably operate thesecond resonant means.

[0055] The second resonant means may further comprise drive means forproducing a switching device drive signal using a pulse voltage havingan opposite polarity to that of the first resonant pulse voltage andinduced in a third coil of the deflection transformer by the firstresonant pulse voltage, and the first switching device may perform aswitching operation in response to the switching device drive signalproduced by the drive means.

[0056] In this case, the first switching device performs the switchingoperation in response to the switching device drive signal producedusing the pulse voltage having an opposite polarity to that of the firstresonant pulse voltage and induced in the third coil of the deflectiontransformer by the first resonant pulse voltage. Accordingly, the secondresonant means can perform the resonance operation in response to theresonance operation performed by the first resonant means, and thesecond resonant pulse voltage can be applied to only the deflection coilin synchronization with the first resonant pulse voltage.

[0057] The drive signal may be a drive signal which is synchronized withthe horizontal frequency.

[0058] In this case, the switching means performs the switchingoperation by the drive signal which is synchronized with the horizontalfrequency. Accordingly, the high voltage deflection circuit according tothe present invention can be used as a horizontal deflection circuit,thereby making it possible to realize a horizontal deflection circuithaving a high operation frequency.

[0059] The first resonant means may comprise an S-correction capacitorconnected in series with the deflection coil, a resonant capacitorconnected in parallel with the deflection coil, the second resonantmeans and the S-correction capacitor, and a damper diode connected inparallel with the resonant capacitor.

[0060] In this case, pincushion distortion can be corrected bymodulating a power supply voltage for a power supply unit.

[0061] The high voltage deflection circuit may further comprise thirdresonant means connected in series with the first resonant means throughthe second resonant means for performing a resonance operation inresponse to the switching operation of the switching means.

[0062] In this case, a high voltage deflection circuit of a diodemodulator type can be realized by the first and third resonant means.

[0063] The first resonant means may comprise a first S-correctioncapacitor connected in series with the deflection coil, a first resonantcapacitor connected in parallel with the deflection coil and the firstS-correction capacitor, and a first damper diode connected in parallelwith the first resonant capacitor, and the third resonant means maycomprise a resonant coil, a second S-correction capacitor connected inseries with the resonant coil, a second resonant capacitor connected inparallel with the resonant coil and the second S-correction capacitor,and a second damper diode connected in parallel with the second resonantcapacitor.

[0064] In this case, a high voltage deflection circuit of a diodemodulator type is constituted by the first and third resonant means.Accordingly, pincushion distortion can be corrected without varying ahigh voltage output generated by the deflection transformer bymodulating a current flowing through the second S-correction capacitor.

[0065] A high voltage deflection circuit according to another aspect ofthe present invention is a high voltage deflection circuit for supplyinga deflection current to a deflection coil, comprising a first resonantcircuit, including the deflection coil, that applies a first resonantpulse voltage to the deflection coil; a switching circuit, connected tothe first resonant circuit, that performs a switching operation inresponse to a predetermined drive signal; and a second resonant circuit,connected in series with the deflection coil and supplied with a drivevoltage by the resonance operation of the first resonant circuit, thatapplies to the deflection coil a second resonant pulse voltage having anopposite polarity to that of the first resonant pulse voltage.

[0066] In the high voltage deflection circuit according to the presentinvention, the second resonant circuit is connected in series with thedeflection coil included in the first resonant circuit, and theswitching circuit that performs the switching operation in response tothe predetermined drive signal is connected to the first resonantcircuit, so that the first resonant pulse voltage is applied to thedeflection circuit by the first resonant circuit, and the secondresonant pulse voltage having an opposite polarity to that of the firstresonant pulse voltage is applied to the deflection coil by the secondresonant circuit.

[0067] At this time, the pulse voltage applied to the deflection coil isthe sum of the first and second resonant pulse voltages, so that a pulsevoltage greater than the first resonant pulse voltage can be applied tothe deflection coil. Further, the second resonant pulse voltage is notapplied to the switching circuit, and only the first resonant pulsevoltage is applied thereto, so that a pulse voltage lower than the pulsevoltage applied to the deflection coil can be applied to the switchingcircuit.

[0068] Consequently, the pulse voltage applied to the deflection coilcan be increased without being limited by the voltage resistance of theswitching circuit. Accordingly, it is possible to increase theinductance value of the deflection coil to improve the opticalcharacteristics and the distortion characteristics of a cathode-ray tubeas well as to reduce a deflection current to reduce power consumption.

[0069] The high voltage deflection circuit may further comprise a thirdresonant circuit, connected in series with the first resonant circuitthrough the second resonant circuit, that performs the resonanceoperation in response to the switching operation performed by theswitching circuit.

[0070] In this case, a high voltage deflection circuit of a diodemodulator type can be realized by the first and third resonant circuits.

BRIEF DESCRIPTION OF DRAWINGS

[0071]FIG. 1 is a block diagram showing the configuration of ahorizontal deflection circuit according to a first embodiment of thepresent invention.

[0072]FIG. 2 is a circuit diagram showing the configuration of thehorizontal deflection circuit shown in FIG. 1.

[0073]FIG. 3 is a timing chart for explaining the operations of thehorizontal deflection circuit shown in FIG. 2.

[0074]FIG. 4 is a circuit diagram showing the configuration of ahorizontal deflection circuit according to a second embodiment of thepresent invention.

[0075]FIG. 5 is a timing chart for explaining the operations of thehorizontal deflection circuit shown in FIG. 4.

[0076]FIG. 6 is a circuit diagram showing the configuration of ahorizontal deflection circuit according to a third embodiment of thepresent invention.

[0077]FIG. 7 is a timing chart for explaining the operations of thehorizontal deflection circuit shown in FIG. 6.

[0078]FIG. 8 is a circuit diagram showing the configuration of a drivecircuit in the horizontal deflection circuit shown in FIG. 6.

[0079]FIG. 9 is a timing chart for explaining the operations of thedrive circuit shown in FIG. 8.

[0080]FIG. 10 is a circuit diagram showing the configuration of ahorizontal deflection circuit according to a fourth embodiment of thepresent invention.

[0081]FIG. 11 is a timing chart showing an example of the configurationof a drive circuit in the horizontal deflection circuit shown in FIG.10.

[0082]FIG. 12 is a timing chart for explaining the operations of thehorizontal deflection circuit shown in FIG. 10 and a timing chart forexplaining the operations at the time of starting a power supply for thedrive circuit shown in FIG. 11.

[0083]FIG. 13 is a circuit diagram showing the configuration of ahorizontal deflection circuit according to a fifth embodiment of thepresent invention.

[0084]FIG. 14 is a circuit diagram showing an example of theconfiguration of a drive circuit in the horizontal deflection circuitshown in FIG. 13.

[0085]FIG. 15 is a timing chart for explaining the operations at thetime of starting a power supply for the drive circuit shown in FIG. 14.

[0086]FIG. 16 is a circuit diagram showing the configuration of ahorizontal deflection circuit according to a sixth embodiment of thepresent invention.

[0087]FIG. 17 is a timing chart for explaining the operations of thehorizontal deflection circuit shown in FIG. 16.

[0088]FIG. 18 is a circuit diagram showing the configuration of ahorizontal deflection circuit according to a seventh embodiment of thepresent invention.

[0089]FIG. 19 is a circuit diagram showing the configuration of ahorizontal deflection circuit according to an eighth embodiment of thepresent invention.

[0090]FIG. 20 is a circuit diagram showing the configuration of ahorizontal deflection circuit according to a ninth embodiment of thepresent invention.

[0091]FIG. 21 is a circuit diagram showing one example of theconfiguration of a conventional horizontal deflection circuit.

[0092]FIG. 22 is a block diagram showing another example of theconfiguration of the conventional horizontal deflection circuit.

[0093]FIG. 23 is a circuit diagram showing the configuration of theconventional horizontal deflection circuit shown in FIG. 22.

[0094]FIG. 24 is a timing chart for explaining the operations of thehorizontal deflection circuit shown in FIG. 23.

BEST MODE FOR CARRYING OUT THE INVENTION

[0095] A horizontal deflection circuit used for a cathode-ray tube in atelevision receiver will be described as an example of a high voltagedeflection circuit according to the present invention. The high voltagedeflection circuit to which the present invention is applied is notparticularly limited to the horizontal deflection circuit. For example,it is similarly applicable to another high voltage deflection circuitsuch as a vertical deflection circuit.

[0096]FIG. 1 is a block diagram showing the configuration of ahorizontal deflection circuit according to a first embodiment of thepresent invention.

[0097] The horizontal deflection circuit shown in FIG. 1 comprises ahorizontal switching transistor (hereinafter referred to as atransistor) Q1, a power supply unit 1, a first resonant circuit 2, asecond resonant circuit 3, and a third resonant circuit 4.

[0098] The transistor Q1 has its collector connected to the power supplyunit 1 and the first resonant circuit 2, its emitted connected to aground, and its base to which a drive pulse DP which is synchronizedwith the horizontal frequency of a video signal displayed on thetelevision receiver is applied.

[0099] The first resonant circuit 2 comprises a horizontal deflectioncoil, and is connected to the power supply unit 1. The third resonantcircuit 4 is connected to a ground terminal. The first resonant circuit2 and the third resonant circuit 4 constitute a horizontal deflectioncircuit of a diode modulator type, and the second resonant circuit 3 isinserted between the first resonant circuit 2 and the third resonantcircuit 4. Consequently, the first resonant circuit 2, the secondresonant circuit 3, and the third resonant circuit 4 are connected inseries in this order, and are connected in parallel with the transistorQ1.

[0100] The first resonant circuit 2 and the third resonant circuit 4 aresupplied with energy from the power supply unit 1, and respectivelyperform resonance operations in response to a switching operationperformed by the transistor Q1, so that a resonant pulse voltage havinga positive polarity is applied to the horizontal deflection coilincluded in the first resonant circuit 2 by the first resonant circuit 2and the third resonant circuit 4. Further, the second resonant circuit 3performs a resonance operation in response to the resonance operationsperformed by the first resonant circuit 2 and the third resonant circuit4, so that a resonant pulse voltage having a negative polarity which isopposite to that of the resonant pulse voltage applied by the firstresonant circuit 2 and the third resonant circuit 4 is applied to thehorizontal deflection coil in the first resonant circuit 2 by the secondresonant circuit 3.

[0101] Consequently, a pulse voltage obtained by adding the resonantpulse voltage having a positive polarity by the first resonant circuit 2and the third resonant circuit 4 and the resonant pulse voltage having anegative polarity by the second resonant circuit 3 is applied to thehorizontal deflection coil, so that a pulse voltage greater than theresonant pulse voltage having a positive polarity by the first resonantcircuit 2 and the third resonant circuit 4 is applied to the horizontaldeflection coil. At this time, the resonant pulse voltage having anegative polarity by the second resonant circuit 3 is not applied to thetransistor Q1, and only the resonant pulse voltage having a positivepolarity by the first resonant circuit 2 and the third resonant circuit4 is applied thereto. Accordingly, a pulse voltage smaller than thepulse voltage applied to the horizontal deflection coil is applied tothe transistor Q1.

[0102]FIG. 2 is a circuit diagram showing the configuration of thehorizontal deflection circuit shown in FIG. 1. The horizontal deflectioncircuit shown in FIG. 2 comprises a transistor Q1, resonant capacitorsC1 and C3, damper diodes D1 and D2, a primary coil L1 of a deflectiontransformer, a horizontal deflection coil L2, a resonant coil L3,S-correction capacitors C2 and C4, a resonant capacitor C5, an FET(Field Effect Transistor; hereinafter abbreviated as a transistor) Q2,first and second coils L5 and L6 on the secondary side of the deflectiontransformer, a smoothing choke coil L4, a smoothing diode D3, and adrive circuit 11.

[0103] One end of the primary coil L1 of the deflection transformer isconnected to a power supply V1, and the other end thereof is connectedto a node N1. The power supply V1 and the primary coil L1 of thedeflection transformer constitute the power supply unit 1 shown inFIG. 1. The transistor Q1 is the transistor Q1 shown in FIG. 1, and hasits collector connected to the node N1.

[0104] The resonant capacitor C1 and the damper diode D1 are connectedin parallel between the node N1 and a node N2. The horizontal deflectioncoil L2 and the S-correction capacitor C2 are connected in seriesbetween the node N1 and the node N2. The resonant capacitor C1, thedamper diode D1, the horizontal deflection coil L2, and the S-correctioncapacitor C2 constitute the first resonant circuit 2 shown in FIG. 1.

[0105] The resonant capacitor C5 is connected in parallel between thenode N2 and a node N3. The transistor Q2 has its source connected to thenode N2, its drain connected to the node N3, and its gate connected tothe drive circuit 11. The transistor Q2 is not particularly limited tothe FET. Another transistor may be used as the transistor Q2. Forexample, an insulation gate-type bipolar transistor (IGBT) that is adevice constructed as one chip by combining an MOS (Metal OxideSemiconductor) FET and a bipolar transistor may be used.

[0106] One end of the smoothing choke coil L4 is connected to the nodeN3, and the other end thereof is connected to the cathode of thesmoothing diode D3. Respective one ends of the first and second coils L5and L6 on the secondary side of the deflection transformer are connectedto the node N2. The other end of the first coil L5 is connected to theanode of the smoothing diode D3. The other end of the second coil L6 isconnected to the drive circuit 11.

[0107] The first and second coils L5 and L6 are electromagneticallycoupled to the primary coil L1 of the deflection transformer. A pulsevoltage having a negative polarity is induced in the first and secondcoils L5 and L6 by the resonant pulse voltage having a positive polaritygenerated by the first resonant circuit 2.

[0108] At this time, a voltage smoothed by the smoothing diode D3 andthe smoothing choke coil L4 is applied to the source of the transistorQ2 as a power supply voltage for the transistor Q2 from the pulsevoltage having a negative polarity in the first coil L5.

[0109] The pulse voltage having a negative polarity induced in thesecond coil L6 is converted into a predetermined drive pulse DPa by thedrive circuit 11, and the drive pulse DPa is supplied to the gate of thetransistor Q2, so that the transistor Q2 is turned on/off in response tothe drive pulse DPa.

[0110] The resonant capacitor C5, the transistor Q2, the smoothing chokecoil L4, the smoothing diode D3, the first and second coils L5 and L6 onthe secondary side of the deflection transformer, and the drive circuit11, described above, constitute the second resonant circuit 3 shown inFIG. 1.

[0111] The resonant capacitor C3 and the damper diode D2 are connectedin parallel between the node N3 and a ground terminal. The resonant coilL3 and the S-correction capacitor C4 are connected in series between thenode N3 and the ground terminal. The resonant capacitor C3, the damperdiode D2, the resonant coil L3, and the S-correction capacitor C4constitute the third resonant circuit 4 shown in FIG. 1.

[0112] In the present embodiment, the first resonant circuit 2corresponds to first resonant means, the second resonant circuit 3corresponds to second resonant means, the third resonant circuit 4corresponds to third resonant means, the transistor Q1 corresponds toswitching means, and the drive circuit 11 corresponds to drive means.The primary coil L1 of the deflection transformer corresponds to a firstcoil of the deflection transformer, the first coil L5 on the secondaryside of the deflection transformer corresponds to a second coil of thedeflection transformer, the second coil L6 on the secondary side of thedeflection transformer corresponds to a third coil of the deflectiontransformer, and the transistor Q2 corresponds to a switching device ora first switching device.

[0113] The operations of the horizontal deflection circuit constructedas described above will be described. FIG. 3 is a timing chart forexplaining the operations of the horizontal deflection circuit shown inFIG. 2. Operations other than operations described below are the same asthose of the normal horizontal deflection circuit of a diode modulatortype and hence, the detailed description thereof is not repeated.

[0114] As shown in FIG. 3, when the transistor Q1 is first renderedconductive (an ON period T2 shown in FIG. 3) upon application of a drivepulse DP which is synchronized with the horizontal frequency to the baseof the transistor Q1, the first and second resonant circuits 2 and 3 aresupplied with energy from the power supply V1 through the primary coilL1 of the deflection transformer, so that a deflection current IC havinga predetermined slope flows through the horizontal deflection coil L2.

[0115] When the transistor Q1 is then rendered non-conductive (an OFFperiod T1 shown in FIG. 3), the first and third resonant circuits 2 and4 perform resonance operations, so that a resonant pulse voltage P1having a positive polarity is generated at both ends of the horizontaldeflection coil L2.

[0116] A pulse voltage having a negative polarity is induced in thefirst and second coils L5 and L6 on the secondary side from the primarycoil L1 of the deflection transformer by the resonant pulse voltagehaving a positive polarity. The pulse voltage having a negative polarityinduced in the first coil L5 is smoothed by the smoothing diode D3 andthe smoothing choke coil L4, and is applied to the drain of thetransistor Q2 as a power supply voltage for the transistor Q2.

[0117] Furthermore, the pulse voltage having a negative polarity inducedin the second coil L6 is converted into a drive pulse DPa by the drivecircuit 11, and the drive pulse DPa obtained by the conversion isapplied to the gate of the transistor Q2. Consequently, the drive pulseDPa is applied to the transistor Q2 in synchronization with theresonance operation performed by the first resonant circuit 2, and thetransistor Q2 performs a switching operation in synchronization with theswitching operation performed by the transistor Q1.

[0118] In such a manner, the second resonant circuit 3 performs theresonance operation in synchronization with the resonance operationsperformed by the first resonant circuit 2 and the third resonant circuit4, so that the resonant pulse voltage P1 having a positive polarity isapplied to the horizontal deflection coil L2 by the first resonantcircuit 2 and the third resonant circuit 4, and a resonant pulse voltageP2 having a negative polarity is applied thereto by the second resonantcircuit 3.

[0119] Here, the resonance operation by the second resonant circuit 3occurs after the resonance operations by the first and third resonantcircuits 2 and 4. The drive pulse DPa for driving the transistor Q2 isgenerated on the basis of a voltage from the second coil L6 such that itenters a low level in the OFF period T1, while entering a high level inthe ON period T2. The resonance operation by the second resonant circuit3 occurs in response to the drive pulse DPa. Accordingly, the pulsewidth of the resonant pulse voltage P2 having a negative polarity isnarrower than the pulse width of the resonant pulse voltage P1 having apositive polarity, as shown in FIG. 3.

[0120] Consequently, the period becomes a margin of the resonant pulsevoltage P2 having a negative polarity with the resonant pulse voltage P1having a positive polarity, thereby making it possible to stablygenerate the resonant pulse voltage P2 having a negative polarity withrespect to the resonant pulse voltage P1 having a positive polarity. Thewaveform of the resonant pulse voltage P2 having a negative polarity isnot particularly limited to the above-mentioned example. Various changescan be made. For example, the pulse width of the resonant pulse voltageP2 having a negative polarity may be made equal to the pulse width ofthe resonant pulse voltage P1 having a positive polarity.

[0121] In such a manner, the resonant pulse voltage P2 having a negativepolarity by the second resonant circuit 3 is applied, in addition to theresonant pulse voltage P1 having a positive polarity by the first andthird resonant circuits 2 and 4, to the horizontal deflection coil L2.Accordingly, a pulse voltage greater than the resonant pulse voltage P1can be applied thereto.

[0122] At this time, the resonant pulse voltage P2 having a negativepolarity by the second resonant circuit 3 becomes a reference voltage onthe side of the cathode of the damper diode D2 in the third resonantcircuit 4. Accordingly, the resonant pulse voltage P2 having a negativepolarity by the second resonant circuit 3 is not applied to thetransistor Q1, and only the resonant pulse voltage P1 having a positivepolarity by the first resonant circuit 2 and the third resonant circuit4 is applied thereto.

[0123] Therefore, a pulse voltage higher than the resonant pulse voltageP1 is applied to the horizontal deflection coil L2 by the first to thirdresonant circuits 2, 3, and 4, and only a resonant pulse voltage P1lower than the pulse voltage applied to the horizontal deflection coilL2 is applied to the transistor Q1 by the first resonant circuit 2 andthe third resonant circuit 4. Accordingly, a pulse voltage higher thanthe voltage resistance of the transistor Q1 can be applied to thehorizontal deflection coil L2.

[0124] In such a manner, in the present embodiment, the pulse voltageapplied to the horizontal deflection coil L2 can be increased withoutbeing limited by the voltage resistance of the transistor Q1.Accordingly, the inductance value of the horizontal deflection coil L2is increased, thereby making it possible to improve the opticalcharacteristics and the distortion characteristics of the cathode-raytube. Further, the inductance value of the horizontal deflection coil L2can be increased, thereby making it possible to reduce a deflectioncurrent flowing through the horizontal deflection coil L2 to reducepower consumption.

[0125] The first and third resonant circuits 2 and 4 constitute ahorizontal deflection circuit of a diode modulator type. Accordingly, acurrent in the S-correction capacitor C4 in the third resonant circuit 4is modulated, thereby making it possible to also correct pincushiondistortion without varying a high voltage output generated by thedeflection transformer.

[0126] A horizontal deflection circuit according to a second embodimentof the present invention will be described. FIG. 4 is a circuit diagramshowing the configuration of a horizontal deflection circuit accordingto the second embodiment of the present invention. FIG. 5 is a timingchart for explaining the operations of the horizontal deflection circuitshown in FIG. 4.

[0127] The horizontal deflection circuit shown in FIG. 4 is the same asthe horizontal deflection circuit shown in FIG. 2 except that the drivecircuit 11 and the second coil L6 on the secondary side of thedeflection transformer are omitted, and a pulse generation circuit 12and a drive circuit 11 a are added. Accordingly, the same portions areassigned the same reference numerals and hence, the detailed descriptionthereof is omitted.

[0128] As shown in FIG. 4, the pulse generation circuit 12 receives adrive pulse DP, and outputs to the drive circuit 11 a a drive signalwhich is synchronized with the drive pulse DP and has a period of a lowlevel and an a period of a high level which are respectively narrowerand wider than those of the drive pulse DP, that is, respectively entersa low level and a high level in an OFF period T1 and an ON period T2shown in FIG. 5. The drive circuit 11 a applies a drive pulse DPb whichis changed in response to the drive signal outputted from the pulsegeneration circuit 12 to the gate of a transistor Q2.

[0129] The present embodiment is the same as the first embodiment exceptthat a resonant capacitor C5, the transistor Q2, a smoothing choke coilL4, a smoothing diode D3, a first coil L5 on the secondary side of adeflection transformer, the pulse generation circuit 12, and the drivecircuit 11 a constitute a second resonant circuit.

[0130] In the above-mentioned manner, the horizontal deflection circuitshown in FIG. 4 also operates, similarly to the horizontal deflectioncircuit shown in FIG. 2. The second resonant circuit can apply aresonant pulse voltage P2 having a negative polarity to a horizontaldeflection coil L2 in synchronization with a resonant pulse voltage P1having a positive polarity by first and third resonant circuits.

[0131] At this time, a reference potential in the drive circuit 11 a isset to a potential on the side of the cathode of a damper diode D2 inthe third resonant circuit 4. Consequently, the resonant pulse voltageP2 having a negative polarity generated when the transistor Q2 driven bythe drive circuit 11 a is rendered non-conductive is applied to only thehorizontal deflection coil L2, and is not applied to a transistor Q1.Also in the present embodiment, the horizontal deflection circuit canthus operate, similarly to that in the first embodiment, thereby makingit possible to obtain the same effect.

[0132] Although in the present embodiment, the drive pulse DPb fordriving the transistor Q2 is produced using the drive pulse DP for thetransistor Q1, the drive pulse for driving the transistor Q2 is notparticularly limited to that in the above-mentioned example, providedthat it is a drive signal which is synchronized with the drive pulse DP.When the drive pulse DP is generated by a microcomputer, for example, asignal which is synchronized with the drive pulse DP may be produced bythe microcomputer, to use the signal as the drive pulse for thetransistor Q2.

[0133] A horizontal deflection circuit according to a third embodimentof the present invention will be described. FIG. 6 is a circuit diagramshowing the configuration of the horizontal deflection circuit accordingto the third embodiment of the present invention.

[0134] The horizontal deflection circuit shown in FIG. 6 comprises ahorizontal switching transistor (hereinafter referred to as atransistor) Q1, a resonant capacitor C1, a damper diode D1, a primarycoil L1 of a deflection transformer, a horizontal deflection coil L2, anS-correction capacitor C2, a resonant capacitor C5, an FET (Field EffectTransistor; hereinafter abbreviated as a transistor) Q2, a smoothingchoke coil L4, a smoothing diode D3, first and second coils L5 and L6 onthe secondary side of the deflection transformer, and a drive circuit11.

[0135] One end of the primary coil L1 of the deflection transformer isconnected to a power supply V1, and the other end thereof is connectedto a node N1. The transistor Q1 has its collector connected to the nodeN1, its emitter connected to a ground, and its base to which a drivepulse DP which is synchronized with the horizontal frequency of a videosignal displayed on a television receiver is applied.

[0136] The resonant capacitor C1 and the damper diode D1 are connectedin parallel between the node N1 and a ground terminal. The horizontaldeflection coil L2 is connected between the node N1 and a node N2. TheS-correction capacitor C2 is connected between a node N3 and the groundterminal. The resonant capacitor C1, the damper diode D1, the horizontaldeflection coil L2, and the S-correction capacitor C2 constitute a firstresonant circuit.

[0137] The resonant capacitor C5 is connected between the node N2 and anode N3. The transistor Q2 has its source connected to the node N2, itsdrain connected to the node N3, and its gate connected to the drivecircuit 11. The transistor Q2 is not particularly limited to an FET.Another transistor may be used. For example, an insulation gate typebipolar transistor (IGBT) or the like that is a device constructed asone chip by combining an MOS (Metal Oxide Semiconductor) FET and abipolar transistor may be used.

[0138] One end of the smoothing choke coil L4 is connected to the nodeN3, and the other end thereof is connected to the cathode of thesmoothing diode D3. One end of each of the first and second coils L5 andL6 on the secondary side of the deflection transformer is connected tothe node N2. The other end of the first coil L5 is connected to theanode of the smoothing diode D3. The other end of the second coil L6 isconnected to the drive circuit 11.

[0139] The first and second coils L5 and L6 are electromagneticallycoupled to the primary coil L1 of the deflection transformer. A pulsevoltage having a negative polarity is induced in the first and secondcoils L5 and L6 by a resonant pulse voltage having a positive polaritygenerated by the first resonant circuit.

[0140] At this time, a voltage smoothed by the smoothing diode D3 andthe smoothing choke coil L4 from the pulse voltage having a negativepolarity in the first coil L5 is applied to the source of the transistorQ2 as a power supply voltage for the transistor Q2.

[0141] Furthermore, the pulse voltage having a negative polarity inducedin the second coil L6 is converted into a predetermined drive pulse DPaby the drive circuit 11, the drive pulse DPa is supplied to the gate ofthe transistor Q2, and the transistor Q2 is turned on/off in response tothe drive pulse DPa.

[0142] The resonant capacitor C5, the transistor Q2, the smoothing chokecoil L4, the smoothing diode D3, the first and second coils L5 and L6 onthe secondary side of the deflection transformer, and the drive circuit11, described above, constitute a second resonant circuit.

[0143] In the present embodiment, the resonant capacitor C1, the damperdiode D1, the horizontal deflection coil L2, and the S-correctioncapacitor C2 correspond to first resonant means, the resonant capacitorC5, the transistor Q2, the smoothing choke coil L4, the smoothing diodeD3, the first and second coils L5 and L6 on the secondary side of thedeflection transformer, and the drive circuit 11 correspond to secondresonant means, the transistor Q1 corresponds to switching means, andthe drive circuit 11 corresponds to drive means. Further, the primarycoil L1 of the deflection transformer corresponds to a first coil of thedeflection transformer, the first coil L5 on the secondary side of thedeflection transformer corresponds to a second coil of the deflectiontransformer, the second coil L6 on the secondary side of the deflectiontransformer corresponds to a third coil of the deflection transformer,and the transistor Q2 corresponds to a switching device.

[0144] The operations of the horizontal deflection circuit constructedas described above will be described. FIG. 7 is a timing chart forexplaining the operations of the horizontal deflection circuit shown inFIG. 6. Operations other than operations described below are the same asthose of the normal horizontal deflection circuit and hence, thedetailed description is omitted.

[0145] As shown in FIG. 7, when the transistor Q1 is rendered conductive(an OFF period T2 shown in FIG. 7) upon application of a drive pulse DPwhich is synchronized with the horizontal frequency to the base of thetransistor Q1, the first resonant circuit is supplied with energy fromthe power supply V1 through the primary coil L1 of the deflectiontransformer, so that a deflection current IC having a predeterminedslope flows through the horizontal deflection coil L2.

[0146] When the transistor Q1 is then rendered non-conductive (an OFFperiod T1 shown in FIG. 7), the first resonant circuit performs aresonance operation, so that a resonant pulse voltage P1 having apositive polarity is generated at both ends of the horizontal deflectioncoil L2.

[0147] A pulse voltage having a negative polarity is induced in thefirst and second coils L5 and L6 on the secondary side from the primarycoil L1 of the deflection transformer by the resonant pulse voltagehaving a positive polarity. The pulse voltage having a negative polarityinduced in the first coil L5 is smoothed by the smoothing diode D3 andthe smoothing choke coil L4, and is applied to the drain of thetransistor Q2 as a power supply voltage for the transistor Q2.

[0148] The pulse voltage having a negative polarity induced in thesecond coil L6 is converted into a drive pulse DPa by the drive circuit11, and the drive pulse DPa obtained by the conversion is applied to thegate of the transistor Q2. Consequently, the drive pulse DPa is appliedto the transistor Q2 in synchronization with the resonance operationperformed by the first resonant circuit, and the transistor Q2 performsa switching operation in synchronization with a switching operationperformed by the transistor Q1.

[0149] In such a manner, the second resonant circuit performs aresonance operation in synchronization with the resonance operationperformed by the first resonant circuit. Accordingly, the resonant pulsevoltage P1 having a positive polarity is applied to the horizontaldeflection coil L2 by the first resonant circuit, and a resonant pulsevoltage P2 having a negative polarity is applied thereto by the secondresonant circuit. Accordingly, a deflection current IC having a slope inthe opposite direction to the predetermined slope flows through thehorizontal deflection coil L2.

[0150] By repeating the above-mentioned operations, a sawtoothdeflection current IC flows through the horizontal deflection coil L2.Consequently, a magnetic field is generated in the horizontal deflectioncoil L2, thereby making it possible to successively deflect electronbeams in the horizontal direction.

[0151] The resonance operation by the second resonant circuit occursafter the resonance operation by the first resonant circuit. The drivepulse DPa for driving the transistor Q2 is controlled by the drivecircuit 11 so as to enter a low level in the OFF period T1, whileentering a high level in the ON period T2. The resonance operation bythe second resonant circuit occurs in response to the drive pulse DPa.Accordingly, the pulse width of the resonant pulse voltage P2 having anegative polarity is narrower than the pulse width of the resonant pulsevoltage P1 having a positive polarity, as shown in FIG. 7.

[0152] Consequently, this period becomes a margin of the resonant pulsevoltage P2 having a negative polarity with the resonant pulse voltage P1having a positive polarity, so that the resonant pulse voltage P2 havinga negative polarity can be stably generated with respect to the resonantpulse voltage P1 having a positive polarity. The waveform of theresonant pulse voltage P2 having a negative polarity is not particularlylimited to that in the above-mentioned example. Various modificationscan be made. For example, the pulse width of the resonant pulse voltageP2 having a negative polarity may be equal to the pulse width of theresonant pulse voltage P1 having a positive polarity.

[0153] In such a manner, the resonant pulse voltage P2 having a negativepolarity by the second resonant circuit is applied, in addition to theresonant pulse voltage P1 having a positive polarity by the firstresonant circuit, to the horizontal deflection coil L2, so that a pulsevoltage greater than the resonant pulse voltage P1 can be appliedthereto.

[0154] At this time, the resonant pulse voltage P2 having a negativepolarity by the second resonant circuit becomes a source voltage of thetransistor Q2 using a ground potential as a basis. Accordingly, theresonant pulse voltage P2 having a negative polarity by the secondresonant circuit is not applied to the transistor Q1, and only theresonant pulse voltage P1 having a positive polarity by the firstresonant circuit is applied thereto.

[0155] Consequently, a pulse voltage higher than the resonant pulsevoltage P1 is applied to the horizontal deflection coil L2 by the firstand second resonant circuits, and only a resonant pulse voltage P1 lowerthan the pulse voltage applied to the horizontal deflection coil L2 isapplied to the transistor Q1 by the first resonant circuit, so that apulse voltage higher than the voltage resistance of the transistor Q1can be applied to the horizontal deflection coil L2.

[0156] In such a manner, in the present embodiment, the pulse voltageapplied to the horizontal deflection coil L2 can be increased withoutbeing limited by the voltage resistance of the transistor Q1.Accordingly, the inductance value of the horizontal deflection coil L2is increased, thereby making it possible to improve the opticalcharacteristics and the distortion characteristics of a cathode-raytube. Further, the inductance value of the horizontal deflection coil L2can be increased, thereby making it possible to reduce a deflectioncurrent flowing through the horizontal deflection coil L2 to reducepower consumption.

[0157]FIG. 8 is a circuit diagram showing an example of theconfiguration of the drive circuit 11 in the horizontal deflectioncircuit shown in FIG. 6. FIG. 9 is a timing chart for explaining theoperations of the drive circuit 11 shown in FIG. 8.

[0158] The drive circuit 11 comprises a transistor Q5, a resistor R1, asmoothing capacitor C8, a smoothing diode D4, and a Zener diode D5. Thetransistor Q5 has its collector connected to the gate of the transistorQ2, its emitter connected to the node N2, and its base connected to theanode of the Zener diode D5. The anode of the smoothing diode D4 and thecathode of the Zener diode D5 are connected to the other end of thesecond coil L6. The cathode of the smoothing diode D4 is connected to anode N4. The smoothing capacitor C8 is connected between the node N2 andthe node N4, and the resistor R1 is connected between the gate of thetransistor Q2 and the node N4.

[0159] A voltage induced in the second coil L6 is smoothed by thesmoothing diode D4 and the smoothing capacitor C8, so that a powersupply voltage for driving the transistor Q5 is produced, and issupplied to the transistor Q5 through the resistor R1. Further, thevoltage induced in the second coil L6 is shifted in a direct-currentmanner by the Zener diode D5, and is applied to the base of thetransistor Q5 such that the transistor Q5 is driven at the timing of apulse of the voltage induced in the second coil L6. Consequently, adrive voltage DPa having a waveform obtained by reversing a base voltagefrom the collector of the transistor Q5 is outputted. The transistor Q2is driven by the drive voltage DPa.

[0160] In the horizontal deflection circuit in the third embodiment, theoperations thereof may, in some cases, be unstable when a power supplyis started in a state where the degree of coupling between the coil L1on the primary side of the deflection transformer and the first andsecond coils L5 and L6 on the secondary side is low. The horizontaldeflection circuit described below is a system for stabilizing theoperations at the time of starting the power supply.

[0161]FIG. 10 is a block diagram showing the configuration of ahorizontal deflection circuit according to a fourth embodiment of thepresent invention. FIG. 12(a) is a timing chart for explaining theoperations of the horizontal deflection circuit shown in FIG. 10. Thehorizontal deflection circuit in the fourth embodiment is a horizontaldeflection circuit using an external power supply system.

[0162] The horizontal deflection circuit shown in FIG. 10 is the same asthe horizontal deflection circuit shown in FIG. 6 except that anexternal power supply 15 is connected to the drive circuit 11. Theconfiguration of the remainder of the horizontal deflection circuitshown in FIG. 10 is the same as the configuration of the horizontaldeflection circuit shown in FIG. 6. The operations at the stationarytime of the horizontal deflection circuit shown in FIG. 10 are the sameas the operations shown in FIG. 7.

[0163] In the horizontal deflection circuit shown in FIG. 10, a drivevoltage is supplied to a transistor Q2 from the external power supply 15before a drive voltage supplied to the transistor Q2 from the drivecircuit 11 rises on the basis of a voltage induced in a second coil L6when a power supply V1 is started.

[0164] In the horizontal deflection circuit shown in FIG. 10, a resonantcapacitor C1, a damper diode D1, a horizontal deflection coil L2, and anS-correction capacitor C2 constitute a first resonant circuit, as in thethird embodiment. The first resonant circuit operates, similarly to thefirst resonant circuit in the third embodiment, so that a resonant pulsevoltage having a positive polarity is applied to the horizontaldeflection coil L2.

[0165] Furthermore, a resonant capacitor C5, a transistor Q2, asmoothing choke coil L4, a smoothing diode D3, first and second coils L5and L6 on the secondary side of a deflection transformer, and the drivecircuit 11 constitute a second resonant circuit. The second resonantcircuit operates, similarly to the second resonant circuit in the thirdembodiment, so that a resonant pulse voltage having a negative polarityis applied to the horizontal deflection coil L2.

[0166] In such a manner, a resonant pulse voltage having a negativepolarity by the second resonant circuit is applied, in addition to aresonant pulse voltage having a positive polarity by the first resonantcircuit, to the horizontal deflection coil L2, so that a greater pulsevoltage can be applied thereto. At this time, the resonant pulse voltagehaving a negative polarity by the second resonant circuit is not appliedto the transistor Q1, and only the resonant pulse voltage having apositive polarity by the first resonant circuit is applied thereto.

[0167] Consequently, also in the present embodiment, the pulse voltageapplied to the horizontal deflection coil L2 can be increased withoutbeing limited by the voltage resistance of the transistor Q1.Accordingly, the same effect as that in the first embodiment can beobtained.

[0168] Here, before the first resonant circuit starts a resonanceoperation upon application of a voltage to a primary coil L1 of thedeflection transformer by application of a drive pulse DP to the base ofthe transistor Q1, a drive voltage is supplied to the transistor Q2 fromthe external power supply 15. That is, the external power supply 15supplies a drive voltage to the gate of the transistor Q2 before thefirst resonant circuit performs the resonance operation. Consequently, asufficient drive voltage can be supplied to the second resonant circuitbefore the first resonant circuit starts the resonance operation,thereby making it possible for the second resonant circuit to stablyperform a resonance operation.

[0169] In the present embodiment, the external power supply 15corresponds to voltage supply means.

[0170]FIG. 11 is a circuit diagram showing an example of theconfiguration of the drive circuit 11 and the external power supply 15in the horizontal deflection circuit shown in FIG. 10. FIG. 12(b) is atiming chart for explaining the operations at the time of starting apower supply for the drive circuit 11 shown in FIG. 11.

[0171] The configuration of the drive circuit 11 shown in FIG. 11 is thesame as the configuration of the drive circuit 11 shown in FIG. 8. Theexternal power supply 15 shown in FIG. 11 comprises a winding L7, asmoothing diode D6, a smoothing capacitor C9, and a reverse flowpreventing diode D7.

[0172] One end of the winding L7 is connected to a node N2, and is setas a floating power supply using the source of the transistor Q2 as abasis. The other end of the winding L7 is connected to the anode of thesmoothing diode D6, and the cathode of the smoothing diode D6 isconnected to the anode of the reverse flow preventing diode D7. Thecathode of the reverse flow preventing diode D7 is connected to a nodeN4. The smoothing capacitor C9 is connected between one end of thewinding L7 and the cathode of the smoothing diode D6.

[0173] As shown in FIG. 12(b), a voltage in the winding L7 is set so asto rise a predetermined time period before a voltage induced in thesecond coil L6 rises. The voltage in the winding L7 is smoothed by thesmoothing diode D6 and the smoothing capacitor C9. The smoothed voltageis supplied to the node N4 through the reverse flow preventing diode D7,and is further supplied as a drive voltage to the gate of the transistorQ2 through a resistor R1.

[0174] Consequently, a sufficient drive voltage can be supplied to thesecond resonant circuit before the first resonant circuit starts theresonance operation, thereby making it possible for the second resonantcircuit to stably perform the resonance operation.

[0175]FIG. 13 is a block diagram showing the configuration of ahorizontal deflection circuit according to a fifth embodiment of thepresent invention. The horizontal deflection circuit in the fifthembodiment is a horizontal deflection circuit using a power supplyswitching system.

[0176] The horizontal deflection circuit shown in FIG. 13 differs fromthe horizontal deflection circuit shown in FIG. 6 in that a switchingtransistor Q3 and a power supply control circuit 13 are furtherprovided.

[0177] The switching transistor Q3 has its collector connected to a DCpower supply V2 used for another circuit in a television receiver. TheDC power supply V2 supplies a power supply voltage V_(cc). The switchingtransistor Q3 has its emitter connected to a drive circuit 11, and itsbase connected to the power supply control circuit 13. The configurationof the remainder of the horizontal deflection circuit shown in FIG. 13is the same as the configuration of the horizontal deflection circuitshown in FIG. 6. The operations at the stationary time of the horizontaldeflection circuit shown in FIG. 13 are the same as the operations shownin FIG. 7.

[0178] The power supply control circuit 13 controls the switchingtransistor Q3 so as to supply the power supply voltage V_(cc) from theDC power supply V2 as a drive voltage for a transistor Q2 only until asecond resonant circuit operates in a state where a first resonantcircuit has not operated yet when a power supply V1 is started.

[0179] Consequently, a sufficient drive voltage can be supplied to asecond resonant circuit before the first resonant circuit starts aresonance operation, thereby making it possible for the second resonantcircuit to stably perform a resonance operation.

[0180] The drive voltage is supplied to the transistor Q2 by the powersupply control circuit 13 until the second resonant circuit starts theresonance operation. Accordingly, the second resonant circuit can stablyoperate without being affected by the resonance operation performed bythe first resonant circuit. Accordingly, the circuit operation can bestably performed as a high voltage horizontal deflection circuit.

[0181] In the present embodiment, the switching transistor Q3 and thepower supply control circuit 13 correspond to voltage supply means, andthe switching transistor Q3 corresponds to a second switching device.

[0182]FIG. 14 is a circuit diagram showing an example of theconfiguration of the drive circuit 11 in the horizontal deflectioncircuit shown in FIG. 13. FIG. 15 is a timing chart for explaining theoperations at the time of starting a power supply for the drive circuit11 shown in FIG. 14.

[0183] The configuration of the drive circuit 11 shown in FIG. 14 is thesame as the configuration of the drive circuit 11 shown in FIG. 8. Theswitching transistor Q3 shown in FIG. 14 has its emitter connected to anode N4 of the drive circuit 11.

[0184] As shown in FIG. 15, the power supply control circuit 13 raises abase voltage of the switching transistor Q3 to a high level when thepower supply V1 is started, to turn the switching transistor Q3 on.Consequently, the power supply voltage V_(cc) from the DC power supplyV2 is supplied to the node N4 of the drive circuit 11, and is furthersupplied as a drive voltage to the gate of the transistor Q2 through aresistor R1. The power supply control circuit 13 turns the switchingtransistor Q3 off before a voltage induced in a second coil L6 rises.

[0185] In such a manner, a sufficient drive voltage can be supplied tothe second resonant circuit before the first resonant circuit starts theresonance operation, thereby making it possible for the second resonantcircuit to stably perform the resonance operation. The transistor Q3 maybe replaced with an MOSFET or a mechanical switch such as a relay.

[0186]FIG. 16 is a circuit diagram showing the configuration of ahorizontal deflection circuit according to a sixth embodiment of thepresent invention. FIG. 17 is a timing chart for explaining theoperations of the horizontal deflection circuit shown in FIG. 16. Thehorizontal deflection circuit in the sixth embodiment is a horizontaldeflection circuit using a current-voltage conversion system (aresonance drive system).

[0187] The horizontal deflection circuit shown in FIG. 16 differs fromthe horizontal deflection circuit shown in FIG. 6 in that the resonantcapacitor C1 is divided into two resonant capacitors C1 a and C1 b, anda drive circuit 16 is provided.

[0188] The drive circuit 16 comprises a transistor Q5, a resistor R1, asmoothing diode D4, a smoothing capacitor C8, a current detectingtransformer CT, and a bridge circuit BR.

[0189] The resonant capacitor C1 a is connected between a node N1 and aground terminal. One end of the resonant capacitor C1 b is connected tothe node N1, and the other end thereof is connected to the groundterminal through a primary winding of the current detecting transformerCT. Both ends of a secondary winding of the current detectingtransformer CT are connected to a pair of terminals of the bridgecircuit BR. The other pair of terminals of the bridge circuit BR isconnected to a node N2 and the base of the transistor Q5. Theconfiguration of the remainder of the horizontal deflection circuitshown in FIG. 6 is the same as the configuration of the horizontaldeflection circuit shown in FIG. 6.

[0190] As shown in FIG. 17, a resonant pulse voltage having a positivepolarity is generated between the collector and the emitter of atransistor Q1 in response to a drive pulse DP. A current correspondingto the resonant pulse voltage flows into the resonant capacitor C1 b,and flows into the primary winding of the current detecting transformerCT. A voltage induced in the secondary winding of the current detectingtransformer CT is full-wave rectified by the bridge circuit BR, and issupplied to the base of the transistor Q5. Consequently, a voltageobtained by reversing a base voltage of the transistor Q5 from thecollector of the transistor Q5 is outputted as a drive voltage. As aresult, a resonant pulse voltage having a negative polarity appearsbetween the source and the drain of the transistor Q5.

[0191] In such a manner, it is possible to drive a transistor Q2 suchthat the transistor Q2 is always turned off when the transistor Q1 isturned off.

[0192] In the horizontal deflection circuit according to the presentembodiment, the control is simple, the necessity of high voltagecomponents is eliminated, and wires are not drawn from the power supplyto the horizontal deflection circuit. Consequently, the circuit scale isreduced, and the cost is lowered.

[0193] A horizontal deflection circuit according to a seventh embodimentof the present invention will be described. FIG. 18 is a circuit diagramshowing the configuration of the horizontal deflection circuit accordingto the seventh embodiment of the present invention. The horizontaldeflection circuit in the seventh embodiment is a horizontal deflectioncircuit using an external power supply system.

[0194] The horizontal deflection circuit shown in FIG. 18 differs fromthe horizontal deflection circuit shown in FIG. 2 in that an externalpower supply 15 is connected to a drive circuit 11. The configuration ofthe drive circuit 11 shown in FIG. 18 is the same as the configurationof the drive circuit shown in FIG. 8. The configuration of the remainderof the horizontal deflection circuit shown in FIG. 18 is the same as theconfiguration of the horizontal deflection circuit shown in FIG. 2.Further, the operations at the stationary time of the horizontaldeflection circuit shown in FIG. 18 are the same as the operations shownin FIG. 3.

[0195] In the horizontal deflection circuit shown in FIG. 18, a drivevoltage is supplied to a transistor Q2 from the external power supply 15before a drive voltage to be supplied to the transistor Q2 from thedrive circuit 11 rises on the basis of a voltage induced in a secondcoil L6 when a power supply V1 is started.

[0196] Here, before a first resonant circuit starts a resonanceoperation upon application of a voltage to a primary coil L1 of adeflection transformer by application of a drive pulse DP to the base ofa transistor Q1, the drive voltage is supplied to the transistor Q2 fromthe external power supply 15. That is, the external power supply 15supplies the drive voltage to the gate of the transistor Q2 before thefirst resonant circuit performs the resonance operation. Consequently, asufficient drive voltage can be supplied to a second resonant circuitbefore the first resonant circuit starts the resonance operation,thereby making it possible for the second resonant circuit to stablyperform a resonance operation.

[0197] In the present embodiment, the external power supply 15corresponds to voltage supply means.

[0198] A horizontal deflection circuit according to an eighth embodimentof the present invention will be described. FIG. 19 is a circuit diagramshowing the configuration of a horizontal deflection circuit accordingto the eighth embodiment of the present invention. The horizontaldeflection circuit in the eighth embodiment is a horizontal deflectioncircuit using a power supply switching system.

[0199] The horizontal deflection circuit shown in FIG. 19 differs fromthe horizontal deflection circuit shown in FIG. 2 in that a switchingtransistor Q3 and a power supply control circuit 13 are furtherprovided.

[0200] The switching transistor Q3 has its collector connected to a DCpower supply V2 used for another circuit in a television receiver. TheDC power supply V2 supplies a power supply voltage V_(cc). The switchingtransistor Q3 has its emitter connected to a drive circuit 11, and itsbase connected to the power supply control circuit 13. The configurationof the drive circuit 11 shown in FIG. 19 is the same as theconfiguration of the drive circuit 11 shown in FIG. 8. The configurationof the remainder of the horizontal deflection circuit shown in FIG. 19is the same as the configuration of the horizontal deflection circuitshown in FIG. 2. Further, the operations at the stationary time of thehorizontal deflection circuit shown in FIG. 19 are the same as theoperations shown in FIG. 3.

[0201] The power supply control circuit 13 controls the switchingtransistor Q3 so as to supply the power supply voltage V_(cc) from theDC power supply V2 as a drive voltage for a transistor Q2 only until asecond resonant circuit operates in a state where a first resonantcircuit has not operated yet when a power supply V1 is started.

[0202] That is, before the first resonant circuit starts a resonanceoperation upon application of a voltage to a primary coil L1 of adeflection transformer by application of a drive pulse DP to the base ofa transistor Q1, the power supply control circuit 13 renders theswitching transistor Q3 conductive, to supply a drive voltage to thetransistor Q2 from the power supply V2.

[0203] The power supply control circuit 13 controls an operation forrendering the switching transistor Q3 conductive/non-conductive so as tostop the supply of the drive voltage when the second resonant circuitstarts a resonance operation. Consequently, a sufficient drive voltagecan be supplied to the second resonant circuit before the first resonantcircuit starts the resonance operation, thereby making it possible forthe second resonant circuit to stably perform the resonance operation.

[0204] The drive voltage is supplied to the transistor Q2 by the powersupply control circuit 13 until the second resonant circuit starts theresonance operation. Accordingly, the second resonant circuit can stablyoperate without being affected by the resonance operation performed bythe first resonant circuit, thereby making it possible to stably performthe above-mentioned circuit operation as a high voltage horizontaldeflection circuit.

[0205] In the present embodiment, the switching transistor Q3 and thepower supply control circuit 13 correspond to voltage supply means, andthe switching transistor Q3 corresponds to a second switching device.

[0206] According to the present invention, a first resonant pulsevoltage is applied to a deflection coil by first resonant means, and asecond resonant pulse voltage having an opposite polarity to that of thefirst resonant pulse voltage is applied to the deflection coil by secondresonant means. The second resonant pulse voltage is not applied toswitching means, and only the first resonant pulse voltage is appliedthereto. Accordingly, a pulse voltage applied to the deflection coil canbe increased without being limited by the voltage resistance of theswitching means, thereby making it possible to increase the inductancevalue of the deflection coil to improve the optical characteristics andthe distortion characteristics of a cathode-ray tube as well as toreduce a deflection current to reduce power consumption.

[0207] Furthermore, the drive voltage is supplied to the second resonantmeans by voltage supply means until the second resonant means starts theresonance operation. Accordingly, the second resonant means can stablyoperate even before the first resonant means performs the resonanceoperation, thereby making it possible to stably perform a circuitoperation.

[0208] The drive circuit 16 in the horizontal deflection circuit shownin FIG. 16 is also applicable to the horizontal deflection circuit shownin FIG. 1. FIG. 20 is a circuit diagram showing the configuration of ahorizontal deflection circuit according to a ninth embodiment of thepresent invention. The horizontal deflection circuit in the ninthembodiment is a horizontal deflection circuit using a current-voltageconversion system (a resonance drive system).

[0209] The horizontal deflection circuit shown in FIG. 20 differs fromthe horizontal deflection circuit shown in FIG. 2 in that two resonantcapacitors C1 a and C1 b are further provided in addition to theresonant capacitor C1, and a drive circuit 16 is provided.

[0210] The drive circuit 16 comprises a transistor Q5, a resistor R1, asmoothing diode D4 and a smoothing capacitor C8, a current detectingtransformer CT, and a bridge circuit BR.

[0211] The resonant capacitor C1 a is connected between a node N1 and aground terminal. One end of the resonant capacitor C1 b is connected tothe node N1, and the other end thereof is connected to the groundterminal through a primary winding of the current detecting transformerCT. Both ends of a secondary winding of the current detectingtransformer CT are connected to a pair of terminals of the bridgecircuit BR. The other pair of terminals of the bridge circuit BR isconnected to a node N2 and the base of the transistor Q5. Theconfiguration of the remainder of the horizontal deflection circuitshown in FIG. 2 is the same as the configuration of the horizontaldeflection circuit shown in FIG. 2. Further, a timing chart forexplaining the operations of the horizontal deflection circuit shown inFIG. 20 is the same as the timing chart shown in FIG. 17.

[0212] As shown in FIG. 17, a resonant pulse voltage having a positivepolarity is generated between the collector and the emitter of atransistor Q1 in response to a drive pulse DP. A current correspondingto the resonant pulse voltage flows into the resonant capacitor C1 b,and flows into the primary winding of the current detecting transformerCT. A voltage induced in the secondary winding of the current detectingtransformer CT is full-wave rectified by the bridge circuit BR, and issupplied to the base of the transistor Q5. Consequently, a voltageobtained by reversing a base voltage of the transistor Q5 from thecollector of the transistor Q5 is outputted as a drive voltage. As aresult, a resonant pulse voltage having a negative polarity appearsbetween the source and the drain of the transistor Q5.

[0213] In such a manner, it is possible to drive a transistor Q2 suchthat the transistor Q2 is always turned off when the transistor Q1 isturned off.

[0214] In the horizontal deflection circuit according to the presentembodiment, the control is simple, the necessity of high voltagecomponents is eliminated, and wires are not drawn from the power supplyto the horizontal deflection circuit. Consequently, the circuit scale isreduced, and the cost is lowered.

[0215] As described in the foregoing, according to the presentinvention, a first resonant pulse voltage is applied to a deflectioncoil by first resonant means (a first resonant circuit), and a secondresonant pulse voltage having an opposite polarity to that of the firstresonant pulse voltage is applied to the deflection coil by secondresonant means (a second resonant circuit). The second resonant pulsevoltage is not applied to switching means (a switching circuit), andonly the first resonant pulse voltage is applied thereto. Accordingly, apulse voltage applied to the deflection coil can be increased withoutbeing limited by the voltage resistance of the switching means(switching circuit), thereby making it possible to increase theinductance value of the deflection coil to improve the opticalcharacteristics and the distortion characteristics of a cathode-ray tubeas well as to reduce a deflection current to reduce power consumption.

[0216] Furthermore, a drive voltage is supplied to the second resonantmeans (second resonant circuit) by voltage supply means until the secondresonant means (second resonant circuit) starts a resonance operation.Accordingly, the second resonant means (second resonant circuit) canstably operate even before the first resonant means (first resonantcircuit) performs a resonance operation, thereby making it possible tostably perform a circuit operation.

1. A high voltage deflection circuit for supplying a deflection currentto a deflection coil, comprising: first resonant means including saiddeflection coil for applying a first resonant pulse voltage to saiddeflection coil; switching means connected to said first resonant meansfor performing a switching operation in response to a predetermineddrive signal; and second resonant means connected in series with saiddeflection coil and supplied with a drive voltage by a resonanceoperation of said first resonant means for applying to said deflectioncoil a second resonant pulse voltage having an opposite polarity to thatof said first resonant pulse voltage.
 2. The high voltage deflectioncircuit according to claim 1, wherein said first resonant means issupplied with electric power through a first coil of a deflectiontransformer connected to a power supply, and said second resonant meanscomprises a resonant capacitor, and a switching device connected inparallel with said resonant capacitor and supplied with a voltageobtained by smoothing a pulse voltage as a power supply voltage, saidpulse voltage having an opposite polarity to that of said first resonantpulse voltage and being induced in a second coil of said deflectiontransformer by said first resonant pulse voltage.
 3. The high voltagedeflection circuit according to claim 2, wherein said second resonantmeans further comprises drive means for producing a switching devicedrive signal using a pulse voltage having an opposite polarity to thatof said first resonant pulse voltage and induced in a third coil of saiddeflection transformer by said first resonant pulse voltage, and saidswitching device performs a switching operation in response to theswitching device drive signal produced by said drive means.
 4. The highvoltage deflection circuit according to claim 2, wherein said secondresonant means further comprises drive means for producing a switchingdevice drive signal on the basis of said drive signal, and saidswitching device performs a switching operation in response to theswitching device drive signal by said drive means.
 5. The high voltagedeflection circuit according to claim 2, wherein said second resonantmeans further comprises current-voltage conversion means for convertinga current flowing through said resonant capacitor into a voltage toproduce a switching device drive signal, and said switching deviceperforms a switching operation in response to the switching device drivesignal produced by said current-voltage conversion means.
 6. The highvoltage deflection circuit according to claim 1, wherein said drivesignal is a drive signal which is synchronized with the horizontalfrequency.
 7. The high voltage deflection circuit according to claim 1,wherein said first resonant means comprises an S-correction capacitorconnected in series with said deflection coil, a resonant capacitorconnected in parallel with said deflection coil, said second resonantmeans and said S-correction capacitor, and a damper diode connected inparallel with said resonant capacitor.
 8. The high voltage deflectioncircuit according to claim 1, further comprising third resonant meansconnected in series with said first resonant means through said secondresonant means for performing a resonance operation in response to theswitching operation of said switching means.
 9. The high voltagedeflection circuit according to claim 8, wherein said first resonantmeans comprises a first S-correction capacitor connected in series withsaid deflection coil, a first resonant capacitor connected in parallelwith said deflection coil and said first S-correction capacitor, and afirst damper diode connected in parallel with said first resonantcapacitor, and said third resonant means comprises a resonant coil, asecond S-correction capacitor connected in series with said resonantcoil, a second resonant capacitor connected in parallel with saidresonant coil and said second S-correction capacitor, and a seconddamper diode connected in parallel with said second resonant capacitor.10. The high voltage deflection circuit according to claim 1, furthercomprising voltage supply means for supplying a drive voltage to saidsecond resonant means until said second resonant means starts aresonance operation.
 11. The high voltage deflection circuit accordingto claim 10, wherein said first resonant means is supplied with electricpower through a first coil of a deflection transformer connected to apower supply, said second resonant means comprises a resonant capacitor,and a first switching device connected in parallel with said resonantcapacitor and supplied with a voltage obtained by smoothing a pulsevoltage as a power supply voltage, said pulse voltage having an oppositepolarity to that of said first resonant pulse voltage and induced in asecond coil of said deflection transformer by said first resonant pulsevoltage, and said voltage supply means supplies the drive voltage tosaid first switching device until said second resonant means starts theresonance operation.
 12. The high voltage deflection circuit accordingto claim 11, wherein said voltage supply means comprises an externalpower supply for supplying the drive voltage to said first switchingdevice until said second resonant means starts the resonance operation.13. The high voltage deflection circuit according to claim 11, whereinsaid voltage supply means comprises a DC power supply, and a secondswitching device that supplies a voltage to said first switching deviceas the drive voltage from said DC power supply until said secondresonant means starts the resonance operation.
 14. The high voltagedeflection circuit according to claim 11, wherein said second resonantmeans further comprises drive means for producing a switching devicedrive signal using a pulse voltage having an opposite polarity to thatof said first resonant pulse voltage and induced in a third coil of saiddeflection transformer by said first resonant pulse voltage, and saidfirst switching device performs a switching operation in response to theswitching device drive signal produced by said drive means.
 15. The highvoltage deflection circuit according to claim 10, wherein said drivesignal is a drive signal which is synchronized with the horizontalfrequency.
 16. The high voltage deflection circuit according to claim10, wherein said first resonant means comprises an S-correctioncapacitor connected in series with said deflection coil, a resonantcapacitor connected in parallel with said deflection coil, said secondresonant means and said S-correction capacitor, and a damper diodeconnected in parallel with said resonant capacitor.
 17. The high voltagedeflection circuit according to claim 10, further comprising thirdresonant means connected in series with said first resonant meansthrough said second resonant means for performing a resonance operationin response to the switching operation of said switching means.
 18. Thehigh voltage deflection circuit according to claim 17, wherein saidfirst resonant means comprises a first S-correction capacitor connectedin series with said deflection coil, a first resonant capacitorconnected in parallel with said deflection coil and said firstS-correction capacitor, and a first damper diode connected in parallelwith said first resonant capacitor, and said third resonant meanscomprises a resonant coil, a second S-correction capacitor connected inseries with said resonant coil, a second resonant capacitor connected inparallel with said resonant coil and said second S-correction capacitor,and a second damper diode connected in parallel with said secondresonant capacitor.
 19. A high voltage deflection circuit for supplyinga deflection current to a deflection coil, comprising: a first resonantcircuit, including said deflection coil, that applies a first resonantpulse voltage to said deflection coil; a switching circuit, connected tosaid first resonant circuit, that performs a switching operation inresponse to a predetermined drive signal; and a second resonant circuit,connected in series with said deflection coil and supplied with a drivevoltage by a resonance operation of said first resonant circuit, thatapplies to said deflection coil a second resonant pulse voltage havingan opposite polarity to that of said first resonant pulse voltage. 20.The high voltage deflection circuit according to claim 19, furthercomprising a voltage supply circuit that supplies a drive voltage tosaid second resonant circuit until said second resonant circuit starts aresonance operation.